D partials and weaks

Question 1

4 groups of altered D

Answer 1

1. Weak D 2. Partial D 3. Del 4. Nonfunctional RhD

Question 2

Weak D

Answer 2

SNPs affect the intracellular domain of the antigen- epitopes not different but ability to place protein in membrane is altered hence low level of expression

Question 3

Weak D types 1-3

Answer 3

not at risk for making anti-D (90% of weak D types for European ancestry)

Question 4

Most common Weak D type and mutation

Answer 4

Weak D type one Valine270Glycine

Question 5

How many weak D types are there

Answer 5

135

Question 6

Ceppelini affect

Answer 6

C in Trans, C on opposite haplotype to D weakens the expression of D, this occurs in r’ phenotype

Question 7

General rule for antibody production in partial D’s

Answer 7

can make anti-D antibody when exposed. Most partial D’s are hybrid genes with a recombination of RhD and RhCE, some partials are due to multiple nucleotide changes

Question 8

DVI new antigen

Answer 8

BARC antigen

Question 9

Rhnull gene nomenclature

Answer 9

RHD*01N non-functioning RhD gene that do not encode full length polypeptide

Question 10

Del

Answer 10

10-30% D negative Asians, antigen can only be detected by elution studies due to faulty transplantation into RBC membrane, due to multiple different RhD mutation. Most associated with r’ phenotype

Question 11

DHAR population

Answer 11

european

Question 12

Crawford population

Answer 12

<0.1% blacks

Question 13

What phenotypes (2) can show strong reactive positive results with certain monoclonal reagents but are negative with others

Answer 13

Crawford and DHAR - both lack expression of ‘conventional’ D and can be sensitized to D

Question 14

Elevated D:

Answer 14

Rare deletion phenotypes D- - D c -, Dcw- , increased expression of D; no/altered or weak expression of C/c, E/e antigens. Hybrid D antigen, RhCE portions being replaced by RhD gene

Question 15

D negative percentages per population

Answer 15

W-15% B 8% A (<0.1%)

Question 16

DHAR positive with what reagents?

Answer 16

Almost all anti-sera except Orthobioclone and polyclonal

Question 17

Crawford positive with what reagents?

Answer 17

negative with all reagents except positive with gammaclone (albuclone?)

Question 18

D negative in europeans

Answer 18

most common D negative is a deletion of entire gene- homozygous for this trait

Question 19

D Psuedogene

Answer 19

in a.a. 37 b.p. insertion into RhD results in a premature stop codon, no functional protein made

Question 20

DVI variant

Answer 20

can make anti-D this is a partial D, very severe HDFN. not detected on bench typically needs a weak D test in order to pick up. Most common partial D in europeans.

Question 21

anti-D reagents composed of:

Answer 21

IgM anti-D to detect at IS, IgG anti-D to detect Weak D during weak D testing. “blended reagent”

Question 22

anti-D column agglutionation

Answer 22

only contains IgM** cannot detect Weak D positive

Question 23

Weak D types 11 and 15

Answer 23

have been shown to make anti-D when exposed. All other types (besides 1-3) we are unsure of the potential of alloimmunization.

Question 24

African american two most common Partial D’s

Answer 24

DIIIa and DAR, both typically test strong positive with anti-D though they can be alloimmunized and often are not recognized as variants until they make the antibody.

Question 25

percentage of hospitalized patients that make anti-D when exposed

Answer 25

30%

Question 26

Requirement for hospitals providing Rh pos to Rh neg

Answer 26

AABB standards require that hospitals have a procedure for providing D negative patients with D positive blood and rhig as it’s not entirely without risk

Question 27

Altered C phenotypes

Answer 27

Cw Cx both have nucleotide changes seen in approximately 2% europeans

Question 28

Altered/partial C

Answer 28

JAHK and JAL african americans

Question 29

Most common partial C

Answer 29

RhD*DIIIa-CE(4-7)-D hybrid. (also without final D) encodes exons 4-7 from CE gene onto RhD gene, however this does not encode D antigen, it encodes a partial C antigen on a D hybrid background. (Most common in a.a.’s 20% D negative a.a.’S have this and inherited with allele: r’s ces. Partial e antigen V- VS+) may be lacking hrb hrs

Question 30

Rh null signature signs

Answer 30

stomatocytes- due to membrane instability

Question 31

hrb and hrs

Answer 31

antigens that are high prevalence associated with partial e- can be produced in conjunction with DIII DAR (partial D’s)

Question 32

Ce

Answer 32

rhi

Question 33

ce

Answer 33

f

Question 34

CE

Answer 34

RH22

Question 35

cE

Answer 35

RH27

Question 36

RHAG antigens

Answer 36

single a.a. substitution makes 4 amino acids: Duclos, Ola, DSLK, RHAG4

Question 37

Proteins that make up Rh complex

Answer 37

RHAG, LW, Rh, GPA, Band3 Duffy, GPC/GPD

Question 38

Rhnull-regulator type

Answer 38

regulator type- nucleotide changes in RHAG implying it’s role in insertion of RH into RBC membrane.

Question 39

Rhnull-amorph

Answer 39

complete deletion of D gene as well as multiple mutations in RhCE

Question 40

E,e, C, c HDFN

Answer 40

ANTI-c causes severe HDFN the other three are not typically associated with HDFN

Question 41

antibodies associated with Rhnull

Answer 41

anti-Rh29 very high prevalence antigen

Question 42

high prevalence antigens in Rh

Answer 42

hrs, hrb, HRb, Hr

Question 43

Do companies have any responsibilities for the reaction to their reagent with partial D’s

Answer 43

FDA mandates the companies are required to list what their specific reagent reacts with, or may not react with. (DIV, DV, DVI)

Question 44

HDFN D negative baby with positive DAT and mom has anti-D in serum

Answer 44

most likely due to ‘blocking affect’ all of mother’s anti-D is bound to fetal red cells therefore anti-sera anti-D cannot bind and appears negative, though actually positive. antibody must be removed with heat elution. increase to 45C can then test eluate for anti-D